Why Mariners will proceed with caution on Jason Bay

Mariners veteran Jason Bay has revived his career in a part-time role this season, which raises the question of whether he should play more often.

Jason Bay has given the Mariners a very interesting “problem” to deal with. It’s the kind of problem the team will be happy to face, given the real problems they’ve had to deal with already this season.

You see, Bay looks to be pretty close to his old self numbers-wise, at least with some stats. He is currently hitting .249 with an on-base percentage of .355 and a .441 slugging mark for an OPS of .787. He’s also on-pace to hit 16 home runs in only 324 at-bats.

Now, some of you, naturally, have seen those numbers and written in to ask me why the Mariners don’t make Bay more of a full-time player. It’s not a bad question: especially when you consider that doubling his at-bats to a more full-time number would make him a 30-homer guy with the OBP you like to see.

Who wouldn’t take outfield numbers like those, right?

Again, though, we’re back to the old John Jaso quandry. Is the player putting up numbers because he’s really a great, underused player? Or is he putting them up because he’s been carefully handled in order to maximize his results?

Again, with Jaso, he put up a .276 average and .850 OPS in 294 at-bats with Seattle last season, prompting criticism by some fans and pundits that he should have played more. But given a 389-at-bat pace by the Oakland Athletics so far this season, Jaso is now a .248 hitter with a .658 OPS. In other words, it appears the Mariners handled Jaso just perfectly last season.

So, what to do with Bay? Well, it’s not that clear-cut an answer, namely because — unlike Jaso — Bay has been a highly successful full-time player before.

Still, Bay is also six years older now than Jaso was last year. That part automatically puts you in different territory, especially when dealing with a player who has a history of injury. Adam Kennedy was once a full-time second baseman for some very good Angels teams.

But by the time he arrived in Seattle in 2011, he was coming off multiple leg injuries and already 35. When Kennedy got off to a hot start, the offense-deprived Mariners decided to use him as a regular player instead of the backup he’d been envisioned as. Injuries played a role in that as well, but the truth is that the Mariners were so bad offensively that the team could not resist sticking Kennedy in the middle of the order and keeping him there as often as possible.

By June 3 of that year, Kennedy was hitting .299 with an .808 OPS for a Mariners squad playing winning baseball and fighting to stay in contention. Mariners manager Eric Wedge kept warning at the time that Kennedy was going to need to get some rest and that offense was going to have to start coming from other places if the team was going to stay in contention.

Sure enough, Kennedy began to falter in June and July under the weight of a season-high 81 and then 82 at-bats in those respective mid-season months. The Mariners began backing him off, but the damage was done and he’d see only 87 at-bats the final two months combined. By season’s end, his once-lofty numbers had dwindled to a .234 average and .632 OPS.

Wedge resisted the urge to overuse Jaso last year, perhaps still conscious of the Kennedy experience. The fact his catching ability wasn’t very good also helped the Mariners avoid putting Jaso on the field daily. They already had a better everyday defensive catcher in Miguel Olivo.

With Bay, his defense has been better than his reputation for it, which would again be an argument for playing him more than Jaso. But again, the Mariners have a good thing going with Bay in the role he was brought here to fill. How much do they really want to push it?

Unlike Jaso, Bay bats right-handed and has his better plattoon splits against southpaw pitching that teams see less of to begin with. Bay is hitting .304 with a .952 OPS against lefties and just .174 with a .588 OPS when facing righties.

“I think we want to put everybody into a position to succeed,” Wedge told me yesterday when I asked him about playing Bay more. “Obviously, I like him better against left-handers, but I like the way he competes against righthanders. He’s getting better and better with that. His plate coverage has been better. He’s been in a better, balanced position. His bat head has been in the zone longer, so there have been a lot of good things that should help him be successful against right-handers too.”

One possibility for Bay to be pressed into additional service — especially against righthanders — involves Michael Saunders, currently mired in a three-week slump in which he’s hit just .152 with a .233 OBP.

Right now, you don’t want Saunders anyplace near the top of the order the way he’s been making outs. The Mariners are using Endy Chavez as their leadoff option against right-handed pitching for now but he’s another guy who can’t be overused at this stage of his career, which might force the Mariners to play the Bay card more often if Saunders can’t start getting on again.

That’s one reason the Mariners need Saunders and other members of the team’s young core to step up and be counted this year. Unlike the plethora of older, more part-time players in their midst, the younger members are more likely to be built to last over the long haul. With Franklin Gutierrez still on the DL and an ongoing health concern, the squad needs Saunders to be a more full-time leadoff option against both-handed pitching.

And if Saunders — and other young guys — can rebound and perform more to the levels expected, then the team can merely continue to take advantage of the big numbers guys like Bay and Raul Ibanez have delivered in the limited roles they were acquired for.

And they can resist the temptation to blow that adavatage by trying to make Bay and others into more than they really should be at this stage.